Ozempic vs. Mounjaro: comparison shows differences in efficacy and price

In 2025, the arrival of Mounjaro in the Brazilian market intensifies comparisons with Ozempic, two drugs widely used for type 2 diabetes control and weight loss. Mounjaro, based on tirzepatide, showed greater efficacy in recent studies, with patients losing up to 22.8 kg, compared to 15 kg with Ozempic, which uses semaglutide. Both drugs belong to the GLP-1 agonist class, but Mounjaro innovates by also acting on the GIP receptor, enhancing appetite reduction. Available since May, Mounjaro costs between R$ 1,406.75 and R$ 2,384.34, while Ozempic prices start at R$ 900, depending on the dose.

The choice between the drugs depends on factors like patient goals, side effects, and cost. Ozempic, established since the 2000s, is more affordable and widely available, but Mounjaro, dubbed the “rich man’s Ozempic,” promises more significant results. Healthcare professionals recommend medical evaluation to determine the best treatment, considering conditions like obesity or uncontrolled diabetes.

Key comparison points include:

• Efficacy: Mounjaro reduces up to 50% more weight than Ozempic.
• Mechanism: Mounjaro targets two hormones, Ozempic one.
• Price: Mounjaro is pricier, with doses up to R$ 2,384.34.
• Availability: Ozempic has broader distribution in Brazil.

Mechanism of action

Mounjaro and Ozempic belong to the GLP-1 agonist class, mimicking the incretin hormone responsible for regulating glucose and reducing appetite. Ozempic, developed in the 1980s, stimulates only the GLP-1 receptor, promoting satiety and lowering blood sugar levels. Mounjaro, introduced in the 2010s, combines action on the GLP-1 receptor with the GIP receptor, amplifying fat burning and metabolic control. This dual-action approach explains its greater efficacy in weight loss.

Studies from 2024 compared the two drugs in randomized clinical trials. Patients using tirzepatide (Mounjaro) lost an average of 22.8 kg after 72 weeks, while those treated with semaglutide (Ozempic) lost 15 kg in the same period. Mounjaro’s dual action also reduces the risk of glycemic spikes, benefiting patients with type 2 diabetes. Both drugs are administered via weekly subcutaneous injections, with doses adjusted per medical guidance.

Choosing the right drug requires individual assessment. Patients with greater insulin resistance may benefit more from Mounjaro, while Ozempic suffices for less severe cases. Consulting an endocrinologist is essential to determine the appropriate dose and protocol.

Efficacy in weight loss

Mounjaro’s primary advantage is its ability to promote greater weight reduction. A 2024 study showed that tirzepatide resulted in 50% more weight loss compared to semaglutide, with patients achieving up to 20% body weight reduction. This difference is attributed to the combined action on GLP-1 and GIP receptors, which more effectively enhances fat burning and reduces hunger.

• Mounjaro: Average loss of 22.8 kg in 72 weeks.
• Ozempic: Average loss of 15 kg in the same period.
• Percentage: Mounjaro reduces up to 20% of body weight, Ozempic up to 14%.
• Speed: Mounjaro shows faster results in 12 weeks.

Ozempic, though less potent, remains effective for patients seeking moderate weight loss or glycemic control. Its long market presence ensures greater trust among doctors, especially for type 2 diabetes patients. Mounjaro, being newer, is still gaining traction, but initial results are promising.

Patients report greater satiety with Mounjaro, facilitating adherence to low-calorie diets. However, both drugs require lifestyle changes, such as balanced nutrition and exercise, to maximize results. Lack of nutritional guidance can limit the benefits of both.

Side effects

Both drugs have side effects, but Mounjaro tends to be better tolerated. Nausea, vomiting, and diarrhea are common in the first months, affecting about 30% of Ozempic patients and 20% of Mounjaro users. Tirzepatide, due to its more selective action, reduces the incidence of gastrointestinal discomfort, per 2024 clinical trials.

• Ozempic: Nausea (30%), diarrhea (15%), risk of pancreatitis.
• Mounjaro: Nausea (20%), constipation (10%), fewer severe events.
• Tolerance: Mounjaro has 10% lower dropout rates due to side effects.
• Rare risks: Both may cause gallbladder issues.

Ozempic, initially designed for diabetes, may cause more side effects in patients without the condition, such as hypoglycemia at improper doses. Mounjaro, developed for both obesity and diabetes, has a safer profile, with fewer treatment discontinuations. Patients with a history of pancreatitis or gallbladder disease should avoid both.

Gradual administration, starting with low doses, minimizes side effects. Doctors recommend beginning with 0.25 mg of Ozempic or 2.5 mg of Mounjaro, increasing every four weeks. Patients should report persistent symptoms, like severe abdominal pain, for immediate evaluation.

Price and accessibility

Cost is a decisive factor in choosing between Mounjaro and Ozempic. In Brazil, Mounjaro launched in May 2025 with prices ranging from R$ 1,406.75 for the 2.5 mg dose to R$ 2,384.34 for the 15 mg dose. Ozempic, well-established, starts at R$ 900 for the 0.5 mg dose, with the 1 mg dose ranging up to R$ 1,200, depending on the region and pharmacy.

Mounjaro’s higher cost reflects its innovation and lack of generics. Ozempic benefits from wider distribution and negotiations with health plans, which partially cover costs in some cases. Patients without coverage bear the full price, making Ozempic more accessible for most.

• Mounjaro: R$ 1,406.75 to R$ 2,384.34 per monthly dose.
• Ozempic: R$ 900 to R$ 1,200 per monthly dose.
• Coverage: Ozempic has broader inclusion in health plans.
• Availability: Mounjaro is still limited in some regions.

Mounjaro’s importation, approved by Anvisa in 2024, increased its availability, but logistics remain a challenge. Major pharmacies in cities like São Paulo and Rio de Janeiro stock the drug, while Ozempic is available nationwide. Patients in remote areas may struggle to access Mounjaro.

Approved indications

Ozempic was initially approved for type 2 diabetes, with off-label use for weight loss gaining popularity. Semaglutide reduces glycemia and body weight, indicated for patients with a body mass index (BMI) above 27 with comorbidities or above 30. Mounjaro, approved for diabetes and obesity, has a broader indication, covering patients with a BMI as low as 25 in some cases.

Mounjaro is particularly effective for patients with severe insulin resistance, while Ozempic suffices for moderate cases. Both require a prescription and regular monitoring of glycemia, kidney function, and other parameters. Use without clinical indication, such as for aesthetic purposes, is discouraged due to risks.